This invention relates generally to the assembly of trusses, and in particular to a locator for holding a structural member at a predetermined position on an assembly apparatus.
Pre-manufactured structural frameworks, such as trusses, are widely used in the construction industry for forming a roof, wall panel, floor, or other building component. Each truss includes a collection of structural members, typically in the form of wooden timbers, held together by connectors, such as connector (“nailing”) plates pressed into the timbers. The truss is assembled to the correct specifications at a factory and then shipped to a construction site. A gantry press apparatus is frequently used to facilitate efficient assembly of the truss. It features a table on which the timbers and connector plates are placed at desired relative positions to form the particular truss configuration.
Conventionally, the table has cylindrically-shaped stops (often referred to as “pucks”) for setting positions of timbers. The stops are slidable along spaced opening channels in the table and are locked at predetermined positions in the channels dependent upon the shape of the truss which is required. The timbers are then located against the stops to define the shape of the truss. Connector plates are placed at locations where adjacent timbers intersect. A motorized roller apparatus (i.e., the gantry) then travels along the table to press integral teeth of the connector plates into the timbers thereby joining them together.
Ideally, each timber should be in tight abutment against adjacent timbers when placed on the table so that the assembled truss will be strong and loads will be effectively transferred between the timbers making up the truss. Unfortunately, some timbers have imperfections, non-linearities, or warp which form one or more gaps between adjacent structural members or between a stop and a structural member. If not eliminated, these gaps would substantially degrade the strength of the assembled truss.
Typically, an operator visually inspects an assembly of structural members prior to activating the roller apparatus. Upon discovering a gap, the operator inserts a wooden wedge between a stop and timber to press the timber into firm engagement with an adjacent timber. Unfortunately, these actions are detrimental to an efficient assembly process and can cause substantial downtime. Wedges are prone to slip or break during installation, fall to the floor at a location from which retrieval is difficult, or be inadvertently nailed into assembly with the truss.
Consequently, some systems of the prior art have featured devices for pressing timbers against adjacent timbers to eliminate gaps. However, these devices have been complex or have been fixedly attached to the apparatus such that it is time consuming to move the device to a second location where gapping occurs, or to another, similar apparatus.